Resilient virtual optical switches over less reliable optical networks

ABSTRACT

In one or more embodiments, one or more systems of a physical optical network that may implement and/or manage a virtual optical network (VON) that interconnects multiple data centers. Virtual nodes based the multiple data centers to be interconnected may be determined, and each of the virtual nodes may be mapped to at least two physical nodes of the physical optical network. Virtual links for pairs of the virtual nodes may be determined, and each virtual link may be mapped to at least one optical network connection of the physical optical network. At least one of a physical node impairment and an optical network connection impairment that is associated with a first physical node implementing a first virtual node may be detected, and the first virtual node may be implemented via a second physical node.

PRIORITY CLAIM

The Present application claims the benefit of priority from U.S.Provisional Patent Application Ser. No. 62/316,152, filed 31 Mar. 2016,entitled “RESILIENT VIRTUAL OPTICAL SWITCHES OVER LESS RELIABLE OPTICALNETWORKS”, which is hereby incorporated by reference for all purposes.

BACKGROUND Field of the Disclosure

The present disclosure relates generally to optical communicationnetworks and, more particularly, to virtual optical networks.

Description of the Related Art

An increasing number of geographically distributed datacenters are beinginterconnected via optical networks, forming wide-area information andcommunications technology (ICT) infrastructures. Cloud applications suchas video content distribution, social networking, and online gaming,among others, rely heavily on such ICT infrastructures for improvedservice quality as well as users' qualities of experiences. Such demandsdrive the need for optical networks with higher capacity, flexibility,and dynamic bandwidth reconfigurability with limited time scales undercloud orchestration systems using software-defined networking (SDN).

Resiliency continues to be a service attribute in optical networking,and virtual optical networks (VONs) are expected to offer high levels ofservice resiliency as well. However, virtual optical network (VON)resiliency solutions assume “reasonably reliable” physical opticalnetworks, where failures usually occur one-at-a-time. New challengesarise when network operators choose to build optical networks withmulti-vendor, mixed-reliability equipment.

SUMMARY

The present disclosure provides one or more systems, of a physicaloptical network, that may implement and/or manage a virtual opticalnetwork (VON) that interconnects multiple data centers, according to oneor more embodiments. A disclosed method that implements and/or managesthe VON may include determining virtual nodes based on the multiple datacenters to be interconnected. Each of the virtual nodes may be mapped toat least two physical nodes of the physical optical network, and thephysical nodes may be provisioned. Virtual links for pairs of thevirtual nodes may be determined. Each virtual link may be mapped to atleast one optical network connection of the physical optical network,and each optical network connection mapped to the virtual links may beprovisioned. At least one of a physical node impairment and an opticalnetwork connection impairment that is associated with a first physicalnode implementing a first virtual node may be detected, and the firstvirtual node may be implemented via a second physical node. In one ormore embodiments, the first virtual node may be implemented via thefirst physical node based on first connectivity to a first data centerof the data centers, where the first connectivity is based on at leastone of a first number of spectrum slots (e.g., wavelengths) and a firstbandwidth, among others. The second physical node may be determined as abackup physical node for the first virtual node based on secondconnectivity to the first data center, where the second connectivity isbased on at least one of a second number of spectrum slots and a secondbandwidth. For example, at least one of the first number of spectrumslots and the first bandwidth may be different from a respective one ofthe second number of spectrum slots and the second bandwidth.

Additional disclosed aspects that implement and/or manage a VON thatinterconnects multiple data centers include a system that implementsand/or manages the VON that interconnect the multiple data centers and anon-transitory computer readable memory device and/or medium storingprocessor-executable instructions, as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and itsfeatures and advantages, reference is now made to the followingdescription, taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 provides a block diagram of selected elements, according to oneor more embodiments;

FIG. 2 provides a block diagram of selected elements of a control systemfor implementing control plane functionality in optical networks,according to one or more embodiments;

FIGS. 3-4B provide bar graphs that illustrate a number of simultaneousnode failures versus a number of occurrences in simulations, accordingto one or more embodiments;

FIG. 5A provides virtual optical network mappings, according to one ormore embodiments;

FIG. 5B illustrates a virtual single big optical switch service,according to one or more embodiments;

FIG. 6 illustrates a resilient virtual optical switch mapping, accordingto one or more embodiments;

FIG. 7 provides a schematic diagram of physical nodes that includecontrol systems, according to one or more embodiments; and

FIG. 8 illustrates a method of operating optical networks, according toone or more embodiments.

DETAILED DESCRIPTION

In the following description, details are set forth by way of example tofacilitate discussion of the disclosed subject matter. It should beapparent to a person of ordinary skill in the field, however, that thedisclosed embodiments are exemplary and not exhaustive of all possibleembodiments.

Throughout this disclosure, a hyphenated form of a reference numeralrefers to a specific instance of an element and the un-hyphenated formof the reference numeral refers to the element generically orcollectively. Thus, as an example (not shown in the drawings), widget“12-1” refers to an instance of a widget class, which may be referred tocollectively as widgets “12” and any one of which may be referred togenerically as a widget “12”. In the figures and the description, likenumerals are intended to represent like elements.

In one or more embodiments, in a Software-Defined Optical Network(SDON), network services may be provided as virtual optical networks(VONs), instead of lightpaths, and virtual optical network (VON)provisioning may be distinguishable from conventional lightpathprovisioning. For example, a lightpath may be a point-to-pointconnection, while a VON may include a network that includes multiplevirtual nodes and virtual links. For instance, a lightpath maycorrespond to a fixed first physical node and a fixed second physicalnode.

In one or more embodiments, each virtual node in a VON may be mapped toone or more physical optical nodes, and each virtual link of a VON maybe mapped to a lightpath coupling corresponding physical optical nodes.For example, a virtual node may be mapped to any physical node within ageographic area or among a number of specified physical nodes, as longas a resulting physical SDON slice satisfies the service-level agreementof the VON. In one or more embodiments, in a VON, a virtual node tophysical node mapping may be flexible. For example, such flexibility mayempower a network service provider to optimize resource usage, reduceservice provisioning costs, and/or provide greater resiliency. Forinstance, the flexibility of VONs may empower network operators tooptimize resource utilization while offering agility and programmabilitytailored to individual services.

In one or more embodiments, VON provisioning may generalize a concept ofoptical networking service from point-to-point fixed-node-pair lightpathprovisioning to multi-point flexible-nodes, or group optical networkslicing. For example, as a lightpath may be a particular instance of aVON including two virtual nodes, each with a fixed node mapping, an SDONservice provider may have backward-compatibility to lightpathprovisioning with little to no modification of its VON serviceprovisioning system.

Furthermore, VON provisioning may be subject to unique constraintsarising from the underlying physical optical network infrastructure,according to one or more embodiments. In one example, one constraintfrom a VON request may be a spectral slot constraint, where a continuouslightpath at a given wavelength, referred to as a “spectral slot”, isdesired by a network customer for a VON request. Because the number ofspectral slots within the physical optical network may be limited,optimal VON provisioning may involve consideration of spectral slotavailability between physical nodes when performing a mapping. Inanother example, another VON constraint may involve distance adaptivemodulation, where different length lightpaths may be considered within agiven VON request. For instance, as a length of a lightpath impacts thecost of the mapping, distance adaptive modulation may be a determiningfactor between different mapping patterns for a VON request. Additionalconstraints for VON requests, such as physical layer impairments, whereadjacent spectral slots may not be used for certain lightpaths, may alsobe associated with VON provisioning.

Moreover, VON provisioning may be associated with general provisioningconstraints, according to one or more embodiments. For example, a VONrequest may be limited to assignment of a physical node to at most onevirtual node specified in the VON request. In one instance, each virtuallink between two virtual nodes in the VON request may be subject to avirtual link capacity constraint for the physical infrastructure. Inanother instance, a VON request may specify certain candidate physicalnodes, which may constrain mapping choices.

In one or more embodiments, resiliency may be a service attribute inoptical networking, and VONs may be expected to offer service resiliencyas well, although the VONs may be implemented with “whiteboxes”. Forexample, whiteboxes may be similar to bare metal generic personalcomputers (PCs), sold by multiple vendors, varying in quality and price.Notwithstanding some vendors may strive to offer whiteboxes withexcellent reliability, products from some other vendors and/or somelow-end models may have less satisfactory (or even unpredictable)reliability.

In one or more embodiments, one or more virtualization capabilities of aSDON may be utilized in providing resilient virtual optical nodes fromless-reliable physical optical nodes. For example, a virtual opticalnode may include virtual nodes and virtual optical connections (e.g.,virtual links). For instance, each of the virtual nodes may be mapped totwo or more physical nodes, and a virtual optical connection, linking apair of virtual nodes, is mapped to an optical network connection thatmay communicatively couple a corresponding physical node pair mapped bya virtual node pair.

In one or more embodiments, a virtual node to physical node mappingand/or a virtual optical connection to optical network connectionmapping may be dynamically updated under network impairments and/orfailures. For example, an availability of a virtual node may be improvedcompared to the physical nodes that implement the virtual nodes. Forinstance, such reliable virtual nodes may offer high-availabilityvirtual optical network services. In one or more embodiments, avirtualized single big optical switch (vSBOS) service may be offeredutilizing a virtual optical node. For example, a datacenter operator mayrequest a vSBOS to interconnect geographically distributed data centers.For instance, the geographically distributed data centers may appear tobe connected to a single “optical” switching hub.

In one or more embodiments, in response to a vSBOS service request, adedicated virtual optical node may be created. For example, each virtualnode of the virtual optical node may be mapped to a primary physicalnode and to one or more backup physical nodes, and each virtual opticalconnection may be mapped to a primary optical network connection and toone or more backup optical network connections, based on connectivityfrom the physical nodes to the data centers interconnected via thevirtual optical node. For instance, after the virtual nodes and thevirtual optical connections are mapped, the vSBOS service may beactivated. In one or more embodiments, in response to an impairmentand/or a failure of one or more of a physical node and an opticalnetwork connection, a virtual node associated with the impairment and/orthe failure and/or a virtual optical connection associated theimpairment and/or the failure may be implemented with a respectivebackup.

Turning now to the drawings, FIG. 1 illustrates an example embodiment ofan optical transport network 101, which may represent an opticalcommunication system. Optical transport network 101 may include one ormore optical fibers 106 configured to transport one or more opticalsignals communicated by components of optical transport network 101. Thenetwork elements of optical transport network 101, coupled together byfibers 106, may comprise one or more transmitters 102, one or moremultiplexers (MUX) 104, one or more optical amplifiers 108, one or moreoptical add/drop multiplexers (OADM) 110, one or more demultiplexers(DEMUX) 105, and one or more receivers 112.

Optical transport network 101 may comprise a point-to-point opticalnetwork with terminal nodes, a ring optical network, a mesh opticalnetwork, or any other suitable optical network or combination of opticalnetworks. Optical fibers 106 comprise thin strands of glass capable ofcommunicating the signals over long distances with very low loss.Optical fibers 106 may comprise a suitable type of fiber selected from avariety of different fibers for optical transmission.

Optical transport network 101 may include devices configured to transmitoptical signals over optical fibers 106. Information may be transmittedand received through optical transport network 101 by modulation of oneor more wavelengths of light to encode the information on thewavelength. In optical networking, a wavelength of light may also bereferred to as a channel. Each channel may be configured to carry acertain amount of information through optical transport network 101.

To increase the information capacity and transport capabilities ofoptical transport network 101, multiple signals transmitted at multiplechannels may be combined into a single wideband optical signal. Theprocess of communicating information at multiple channels is referred toin optics as wavelength division multiplexing (WDM). Coarse wavelengthdivision multiplexing (CWDM) refers to the multiplexing of wavelengthsthat are widely spaced having low number of channels, usually greaterthan 20 nm and less than sixteen wavelengths, and dense wavelengthdivision multiplexing (DWDM) refers to the multiplexing of wavelengthsthat are closely spaced having large number of channels, usually lessthan 0.8 nm spacing and greater than forty wavelengths, into a fiber.WDM or other multi-wavelength multiplexing transmission techniques areemployed in optical networks to increase the aggregate bandwidth peroptical fiber. Without WDM, the bandwidth in optical networks may belimited to the bit-rate of solely one wavelength. With more bandwidth,optical networks are capable of transmitting greater amounts ofinformation. Optical transport network 101 may be configured to transmitdisparate channels using WDM or some other suitable multi-channelmultiplexing technique, and to amplify the multi-channel signal.

Optical transport network 101 may include one or more opticaltransmitters (Tx) 102 configured to transmit optical signals throughoptical transport network 101 in specific wavelengths or channels.Transmitters 102 may comprise a system, apparatus or device configuredto convert an electrical signal into an optical signal and transmit theoptical signal. For example, transmitters 102 may each comprise a laserand a modulator to receive electrical signals and modulate theinformation contained in the electrical signals onto a beam of lightproduced by the laser at a particular wavelength, and transmit the beamfor carrying the signal throughout optical transport network 101.

Multiplexer 104 may be coupled to transmitters 102 and may be a system,apparatus or device configured to combine the signals transmitted bytransmitters 102, e.g., at respective individual wavelengths, into a WDMsignal.

Optical amplifiers 108 may amplify the multi-channeled signals withinoptical transport network 101. Optical amplifiers 108 may be positionedbefore and after certain lengths of fiber 106. Optical amplifiers 108may comprise a system, apparatus, or device configured to amplifyoptical signals. For example, optical amplifiers 108 may comprise anoptical repeater that amplifies the optical signal. This amplificationmay be performed with opto-electrical or electro-optical conversion. Insome embodiments, optical amplifiers 108 may comprise an optical fiberdoped with a rare-earth element to form a doped fiber amplificationelement. When a signal passes through the fiber, external energy may beapplied in the form of a pump signal to excite the atoms of the dopedportion of the optical fiber, which increases the intensity of theoptical signal. As an example, optical amplifiers 108 may comprise anerbium-doped fiber amplifier (EDFA).

OADMs 110 may be coupled to optical transport network 101 via fibers106. OADMs 110 comprise an add/drop module, which may include a system,apparatus or device configured to add or drop optical signals (i.e., atindividual wavelengths) from fibers 106. After passing through an OADM110, an optical signal may travel along fibers 106 directly to adestination, or the signal may be passed through one or more additionalOADMs 110 and optical amplifiers 108 before reaching a destination.

In certain embodiments of optical transport network 101, OADM 110 mayrepresent a reconfigurable OADM (ROADM) that is capable of adding ordropping individual or multiple wavelengths of a WDM signal. Theindividual or multiple wavelengths may be added or dropped in theoptical domain, for example, using a wavelength selective switch (WSS)(not shown) that may be included in a ROADM.

As shown in FIG. 1, optical transport network 101 may also include oneor more demultiplexers 105 at one or more destinations of network 101.Demultiplexer 105 may comprise a system apparatus or device that acts asa demultiplexer by splitting a single composite WDM signal intoindividual channels at respective wavelengths. For example, opticaltransport network 101 may transmit and carry a forty (40) channel DWDMsignal. Demultiplexer 105 may divide the single, forty channel DWDMsignal into forty separate signals according to the forty differentchannels.

In FIG. 1, optical transport network 101 may also include receivers 112coupled to demultiplexer 105. Each receiver 112 may be configured toreceive optical signals transmitted at a particular wavelength orchannel, and may process the optical signals to obtain (e.g.,demodulate) the information (i.e., data) that the optical signalscontain. Accordingly, network 101 may include at least one receiver 112for every channel of the network.

Optical networks, such as optical transport network 101 in FIG. 1, mayemploy modulation techniques to convey information in the opticalsignals over the optical fibers. Such modulation schemes may includephase-shift keying (PSK), frequency-shift keying (FSK), amplitude-shiftkeying (ASK), and quadrature amplitude modulation (QAM), among otherexamples of modulation techniques. In PSK, the information carried bythe optical signal may be conveyed by modulating the phase of areference signal, also known as a carrier wave, or simply, a carrier.The information may be conveyed by modulating the phase of the signalitself using two-level or binary phase-shift keying (BPSK), four-levelor quadrature phase-shift keying (QPSK), multi-level phase-shift keying(M-PSK) and differential phase-shift keying (DPSK). In QAM, theinformation carried by the optical signal may be conveyed by modulatingboth the amplitude and phase of the carrier wave. PSK may be considereda subset of QAM, wherein the amplitude of the carrier waves ismaintained as a constant. Additionally, polarization divisionmultiplexing (PDM) technology may enable achieving a greater bit ratefor information transmission. PDM transmission comprises modulatinginformation onto various polarization components of an optical signalassociated with a channel. The polarization of an optical signal mayrefer to the direction of the oscillations of the optical signal. Theterm “polarization” may generally refer to the path traced out by thetip of the electric field vector at a point in space, which isperpendicular to the propagation direction of the optical signal.

In an optical network, such as optical transport network 101 in FIG. 1,it is typical to refer to a management plane, a control plane, and atransport plane (sometimes called the physical layer). A centralmanagement host (not shown) may reside in the management plane and mayconfigure and supervise the components of the control plane. Themanagement plane includes ultimate control over all transport plane andcontrol plane entities (e.g., network elements). As an example, themanagement plane may consist of a central processing center (e.g., thecentral management host), including one or more processing resources,data storage components, etc. The management plane may be in electricalcommunication with the elements of the control plane and may also be inelectrical communication with one or more network elements of thetransport plane. The management plane may perform management functionsfor an overall system and provide coordination between network elements,the control plane, and the transport plane. As examples, the managementplane may include an element management system (EMS), which handles oneor more network elements from the perspective of the elements, a networkmanagement system (NMS), which handles many devices from the perspectiveof the network, and an operational support system (OSS), which handlesnetwork-wide operations.

Modifications, additions or omissions may be made to optical transportnetwork 101 without departing from the scope of the disclosure. Forexample, optical transport network 101 may include more or fewerelements than those depicted in FIG. 1. Also, as mentioned above,although depicted as a point-to-point network, optical transport network101 may comprise any suitable network topology for transmitting opticalsignals such as a ring, a mesh, or a hierarchical network topology.

As discussed above, the amount of information that may be transmittedover an optical network may vary with the number of optical channelscoded with information and multiplexed into one signal. Accordingly, anoptical fiber employing a WDM signal may carry more information than anoptical fiber that carries information over a single channel. Besidesthe number of channels and number of polarization components carried,another factor that affects how much information can be transmitted overan optical network may be the bit rate of transmission. The higher thebit rate, the greater the transmitted information capacity. Achievinghigher bit rates may be limited by the availability of wide bandwidthelectrical driver technology, digital signal processor technology andincrease in the required OSNR for transmission over optical transportnetwork 101.

As shown in FIG. 1, optical transport network 101 may employ a digitalwrapper technology to encapsulate existing frames of data, which mayoriginate in a variety of native protocols, and may add packetizedoverhead for addressing, management, and quality assurance purposes. Theresulting optical signal, in the form of optical data units (ODUs) maythen be transported using individual optical wavelengths by opticaltransport network 101. The packetized overhead may be used to monitorand control the optical signals being transported using any of a varietyof different protocols. In particular embodiments, operation of opticaltransport network 101 is performed according to optical transportnetworking (OTN) standards or recommendations promulgated by theInternational Telecommunications Union (ITU), such as ITU-TG.709—“Interfaces for the Optical Transport Network” and ITU-TG.872—“Architecture of the Optical Transport Network”, among others. Theoptical wavelengths in OTN may rely on a hierarchical implementation oftime-division multiplexing (TDM) to optimize carrier wavelengthefficiency.

As a result of the hierarchical TDM arrangement of the optical signalsin OTN, OTN switching may be performed at different sub-wavelength bitrates along optical transport network 101. As used herein, OTN switchingrefers to switching at ODU paths of different bit rates with the ODUbeing the atomic unit of switching. In contrast, Internet protocol (IP)switching, such as by an IP router, refers to switching of networksignals where an individual IP packet is the atomic unit of switching.In OTN switching, such as in optical transport network 101, an ODUremains in the optical domain outside of an OTN switch from networkingress to network egress. Within the OTN switch, an ODU may be accessedas an electrical domain object and OTN switching may include electricalswitching technology.

It is noted that while OTN switching does generally take place in theoptical wavelength domain (DWDM), ROADMs and DWDM may be formallyreferred to as layer0 technologies (in The Basic Reference Model forOpen Systems Interconnection, also referred to as the OSI ReferenceModel). In contrast, OTN may be described as a layer1 technology in theOSI Reference Model, which may operate independently of the opticalwavelength domain (DWDM). For example, an OTN switch may theoreticallyoperate over dark fiber, galvanic conductors (such as copper), or over awireless medium (such as a millimeter-scale wave, or radio frequencies).

In an optical network, such as optical network 101 in FIG. 1, it istypical to refer to a management plane, a control plane, and a transportplane (sometimes called the physical layer). A management host (notshown) may reside in the management plane and may configure andsupervise the components of the control plane. The management planeincludes ultimate control over all transport plane and control planeentities (e.g., network elements). As an example, the management planemay include a central processing center (e.g., the central managementhost), including one or more processing resources, data storagecomponents, etc. The management plane may be in electrical communicationwith the elements of the control plane and may also be in electricalcommunication with one or more network elements of the transport plane.The management plane may perform management functions for an overallsystem and provide coordination between network elements, the controlplane, and the transport plane. As examples, the management plane mayinclude an element management system (EMS) that may handle one or morenetwork elements from the perspective of the elements, a networkmanagement system (NMS) that may handle many devices from theperspective of the network, and/or an operational support system (OSS)that may handle network-wide operations.

In general, the term “distributed” may refer to multiple nodes, ornetwork elements (NEs), interconnected by a network and a set ofcollaborating nodes (or NEs). As used herein, the term “disaggregated”may refer to a NE in a distributed network that is further reorganizedinto a set of disaggregated sub-components in a physical sense, ascompared to an aggregated physical structure, while maintaining thefunctionality of an integrated NE in a logical sense. In someembodiments, the disaggregated sub-components may be made openlyaccessible, in contrast to the aggregated physical structure.

Turning now to FIG. 2 a block diagram of selected elements of a controlsystem 200 for implementing control plane functionality in opticalnetworks, such as, for example, in optical network 101 (see FIG. 1), isillustrated, according to one or more embodiments. As shown controlsystem 200 may include a processor 208 and a memory device 220,communicatively coupled to processor 208. In one or more embodiments,memory device 220 may store executable instructions in the form ofexecutable code that may be executable by processor 208 to performand/or implement one or more functions and operations described herein.

In one or more embodiments, memory device 220 may include one or more ofpersistent media, volatile media, fixed media, removable media, magneticmedia, and semiconductor media, among others. Memory device 220 mayinclude one or more non-transitory computer-readable media that storesdata and/or instructions for at least a period of time. Memory device220 may include storage media or storage devices such as a direct accessstorage device (e.g., a hard disk drive or floppy disk), a sequentialaccess storage device (e.g., a tape disk drive), compact disk (CD),random access memory (RAM), read-only memory (ROM), CD-ROM, digitalversatile disc (DVD), electrically erasable programmable read-onlymemory (EEPROM), and/or flash memory; non-transitory media; and/orvarious combinations of the foregoing. Memory device 220 may be operableto store instructions, data, or both.

As shown, memory device may include sets and/or sequences ofinstructions that may represent executable computer programs. Forexample, memory device may include a path computation engine module 202,a signaling module 206, a routing module 210, a discovery module 212,and a vSBOS module 214, among others. In one or more embodiments, pathcomputation engine 202, in conjunction with signaling module 206,discovery module 212, routing module 210, and vSBOS module 214 mayrepresent instructions and/or code for implementing one or more systems,processes, flowcharts, and/or methods described herein.

In one or more embodiments, a control plane may include functionalityfor network intelligence and control and may include applications thatsupport an ability to establish network services, including applicationsand/or modules for discovery, routing, path computation, signaling,vSBOS provisioning, and/or vSBOS management, among others. For example,the control plane applications executed by control system 200 may worktogether to automatically establish services within the optical network.In one instance, discovery module 212 may discover local linksconnecting to neighbors. In a second instance, routing module 210 maybroadcast local link information to optical network nodes whilepopulating a database 204. In a third instance, a path computationengine 202 may be utilized to compute a network path utilizing database204, when a request for service from the optical network is received. Ina fourth instance, a signaling module 206 may establish a requestedservice after receiving the network path from path computation engine202. In another instance, a vSBOS module 214 may be utilized in vSBOSservice provisioning and/or vSBOS service management. In one or moreembodiments, one or more of modules 202 through 214 may access and/orutilize database 204 in performing one or more described functionalitiesdescribed. For example, database 204 may store information associatedwith one or more backup physical nodes and/or one or more backup opticalnetwork connections that may be utilized by vSBOS module 214 inproviding vSBOS service provisioning and/or vSBOS service management.

In one or more embodiments, control system 200 may be configured tointerface with a user (not shown) and/or receive data about an opticalsignal transmission path. For example, control system 200 may includeand/or may be coupled to one or more input devices and/or output devicesto facilitate receiving data about the optical signal transmission pathfrom the user and/or outputting results to the user. For instance theone or more input and/or output devices (not shown) may include one ormore of a keyboard, a mouse, a touchpad, a microphone, a display, atouchscreen display, an audio speaker, among others. In one or moreembodiments, control system 200 may be configured to receive data aboutthe optical signal transmission path from a device such as anothercomputing device and/or a network element (not shown).

In one or more embodiments, vSBOS module 214 may be configured toprovide provisioning and/or resilient virtual optical nodes fromless-reliable physical optical nodes. In one example, vSBOS module 214may create and/or implement a dedicated virtual optical node in responseto a vSBOS service request. In a second example, vSBOS module 214 maymap each virtual node of a virtual optical node to two or more physicalnodes and/or may map a virtual optical connection, linking a pair ofvirtual nodes, and may map an optical network connection that maycommunicatively couple a corresponding physical node pair mapped by avirtual node pair. For instance, vSBOS module 214 may map each virtualnode of the virtual optical node to a primary physical node and to oneor more backup physical nodes, and vSBOS module 214 may map each virtualoptical connection to a primary optical network connection and to one ormore backup optical network connections, based on connectivity from thephysical nodes to data centers interconnected via the virtual opticalnode. In another example, vSBOS module 214 may dynamically update avirtual node to physical node mapping and/or a virtual opticalconnection to optical network connection mapping in response to networkimpairments and/or failures. For instance, vSBOS module 214 mayimplement a virtual node associated with the impairment and/or thefailure and/or may implement a virtual optical connection associatedwith the impairment and/or the failure with a respective backup.

In one or more embodiments, discovery module 212 may be configured toreceive data concerning an optical signal transmission path in anoptical network and may be responsible for discovery of neighbors andlinks between neighbors. For example, discovery module 212 may senddiscovery messages according to a discovery protocol, and may receivedata about the optical signal transmission path. In one or moreembodiments, discovery module 212 may determine one or more features,such as, one or more of a fiber type, a fiber length, a number and/ortype of components, a data rate, a modulation format of the data, ainput power of the optical signal, a number of signal carryingwavelengths (e.g., channels), a channel spacing, a traffic demand, and anetwork topology, among others.

In one or more embodiments, routing module 210 may be responsible forpropagating link connectivity information to various nodes within anoptical network, such as optical network 101. For example, routingmodule 210 may populate database 204 with resource information tosupport traffic engineering, which may include link bandwidthavailability. For instance, routing module 210 may populate database 204with information usable to determine a network topology of an opticalnetwork.

In one or more embodiments, path computation engine 202 may beconfigured to utilize information stored via database 204 to determinetransmission characteristics of an optical signal transmission path. Forexample, the transmission characteristics of the optical signaltransmission path may be utilized in determining how transmissiondegradation factors, such as chromatic dispersion, nonlinear effects,polarization effects (e.g., polarization mode dispersion, polarizationdependent loss, etc.), amplified spontaneous emission and/or others mayaffect optical signals within the optical signal transmission path. Forinstance, in determining the transmission characteristics of the opticalsignal transmission path, path computation engine 202 may utilizeinterplay between the transmission degradation factors. In one or moreembodiments, path computation engine 202 may generate values fortransmission degradation factors and/or may store data describing theoptical signal transmission path via database 204.

In one or more embodiments, signaling module 206 may provide one or morefunctionalities associated with one or more of setting up, modifying,and tearing down end-to-end networks services in an optical network(e.g., optical network 101), among others. For example, when an ingressnode in the optical network receives a service request, control system200 may employ signaling module 206 to request a network path from pathcomputation engine 202 that may be optimized according to differentcriteria, such as bandwidth, cost, etc., and when the desired networkpath is identified, signaling module 206 may communicate with respectivenodes along the network path to establish the requested networkservices. In one or more embodiments, signaling module 206 may employ asignaling protocol that propagates subsequent communication to and/orfrom nodes along the network path.

In operation of VON provisioning utilizing implicit encoding of mappingconstraints, as described herein, control system 200 may representand/or include a SDON controller, while path computation engine 202 mayinclude functionality for mapping pattern search and evaluation usingimplicit encoding of mapping constraints, for example. In this manner,for instance, control system 200 may apply different mapping constraintsto select an optimal mapping pattern, such as routing and spectral slotassignments, according to the specific lightpaths requested in one ormore VON requests.

In one or more embodiments, utilizing a search that includes a branchand bound search methodology, mapping choices, representing partialmapping patterns that potentially satisfy one or more VON requests, maybe evaluated and/or may be rejected based on the mapping constraintsbefore a complete mapping pattern is generated, while remaining mappingchoices that are not rejected may result in valid mapping patterns. Whenat least one valid mapping pattern results from the search, the VONrequest may be satisfied. When multiple valid mapping patterns resultfrom the evaluation, the SDON controller may select a final mappingpattern based on a lowest occupied number of spectral slots, which hasthe smallest overall spectral slot usage. In one or more embodiments, afinal mapping pattern may be selected based on a lowest spectral slotlayer when inter-channel impairments may be present and/or whendesirable for optical network operation. It is noted that the searchdescribed herein may provide valid mapping patterns without iterationover the entire space of mapping choices. The SDON controller mayproceed to reserve the physical network resources according to theselected valid mapping pattern to service the VON request. When no validmapping patterns are available, the VON request may not be satisfiedand/or may be denied.

Turning now to FIGS. 3 through 4B, bar graphs that illustrate a numberof simultaneous node failures versus a number of occurrences insimulations are provided, according to one or more embodiments. A bargraph 300 of FIG. 3 utilizes data associated with a DTnet (e.g., 14nodes with 19 links) topology to simulate network failure events causedby equipment failures, and a bar graph 400 of FIGS. 4A and 4B utilizesdata associated with a CORONET (e.g., 75 nodes with 99 links) topologyto simulate network failure events caused by equipment failures. Forexample, the equipment subject to failure includes “whiteboxes”. Forinstance, as discussed above, whiteboxes may be similar to bare metalgeneric personal computers (PCs), sold by multiple vendors, varying inquality and price. Although some vendors may strive to offer whiteboxeswith excellent reliability, products from some other vendors and/or somelow-end models may have less satisfactory (or even unpredictable)reliability.

The simulations assume that all nodes in the network are whiteboxes withthe same level of Node Availability (NA). For example, the NA can bedefined as NA=MTTF/(MTTF+MTTR), where MTTF stands for Mean Time ToFailure and MTTR stands for Mean Time To Repair. For instance, if eachnode operates continuously for an average of ninety-nine (99) daysbefore failure occurs (MTTF=99 days), where it can take an average ofone (1) day to repair/replace the node (MTTR=1 day), thenNA=99/(99+1)=0.99.

During simulation, each node's failure/recovery events occurindependently, and a node failure event can follow Poisson arrival,where a time duration for a node recovery follows negative exponentialdistribution. Each simulation runs for 10,950 time units (correspondingto 30 years when one (1) time unit=one (1) day) with a certain NA, whichis gradually lowered from 0.9999 (roughly 1 failure every 10,000 days=27years) to 0.95 (1 failure every 20 days) per simulation iteration. It isnoted that these simulations do not include link failure events (e.g.,fiber cut, etc.) independently. In these simulations, a link goes downwhen a node that the link connects to goes down, and the link comes backon when both nodes the link connects return to working conditions.

FIG. 3 illustrates a histogram of occurrence of simultaneous nodefailures in DTnet, and FIGS. 4A and 4B illustrate a histogram ofoccurrence of simultaneous node failures in CORONET. The histograms wereobtained as follows. Every time a network encounters a new nodefailure/recovery event, a time interval between a current event and aprevious event constitutes a time period. For each time period, a totalnumber of nodes in the network that are currently in failure state arecounted. If, during a simulation there are four (4) time periods wherethere is no node failure across a network, three (3) time periods wherethere is one node failure, and two (2) time periods where there are twosimultaneous node failures, then the occurrences of 0, 1 and 2simultaneous-node-failures are 4, 3 and 2, respectively. As shown inFIGS. 3 through 4B, with NA=0.9999, both DTnet and CORONET have eitherfailure-free operation, or encounter a small number of single-nodefailures.

With optical network equipment engineered with such high reliabilityexisting resiliency solutions against single node/link failure wouldsuffice. Although, with NA=0.999, DTnet and CORONET begin to experiencetwo-simultaneous-node-failures. With NA=0.99 and below, simultaneousnode failures become predominant in DTnet and CORONET, and CORONETsuffers more higher-count simultaneous-node-failures (such as fivenine-simultaneous-node-failures with NA=0.97 and fourteeneleven-simultaneous-node-failures with NA=0.95) due to a larger nodecount of CORONET. For example, a node availability of 0.999 correspondsto around a three-year product lifecycle (similar to datacenter servers'replacement cycle), and simultaneous node failures become common innetworks built with NA 0.999 and below. As such, it may be important tohave one or more robust resiliency solutions in place when operating oneor more optical networks with potentially less-reliable whiteboxes.

Turning now to FIG. 5A, virtual optical network mappings 500 areprovided, according to one or more embodiments. As shown, physical nodes503 may be distributed in a geographic region 501. In one or moreembodiments, a physical node 503 may include one or more computingsystems and/or one or more networking devices. For example, a physicalnode 503 may include one or more systems, devices, and/orfunctionalities that may be utilized to implement one or more opticalnetwork systems and/or one or more VONs.

As illustrated, geographically distributed data centers such as physicalnodes 503 may be interconnected via optical network connections 504. Inone or more embodiments, physical nodes 503 and optical networkconnections 504 may form a wide area information and communicationtechnology (ICT) infrastructure that may be utilized in variousapplications and/or provide high capacity, flexibility, and/or dynamicbandwidth reconfiguration on shorter time scales. In one example,applications such as video content distribution applications may rely onone or more ICT infrastructures to improve users' quality of experience.In another example, applications such as cloud orchestrationapplications may utilize one or more optical networks and/or one or moreICT infrastructures to provide higher capacity, flexibility and dynamicbandwidth reconfiguration on shorter time scale utilizing one or moresoftware defined networks (SDNs). In one or more embodiments, inmulti-tenancy inter-data center network, optical network virtualizationmay enable network operators to provision multiple coexisting andisolated VONs over same one or more physical infrastructures.

As shown, a first VON may include virtual nodes 502-1, 502-2, and 502-3,and a second VON may include virtual nodes 502-4, 502-5, 502-6, and502-7. Illustrated via dashed lines, virtual nodes 502-1 through 502-3may be mapped to physical nodes 503-7, 503-55, and 503-28, respectively,and virtual nodes 502-4 through 502-7 may be mapped to physical nodes503-44, 503-10, 503-11, and 503-51, respectively.

Turning now to FIG. 5B, a virtual single big optical switch service 505is illustrated, according to one or more embodiments. As shown, acustomer view may include a vSBOS 510. In one or more embodiments, adisplay and/or screen of a customer may display the customer view. Forexample, a graphical user interface (GUI) may display the customer view,and the customer may configure vSBOS 510 and/or manage data center (DC)couplings to vSBOS 510 via the GUI. As illustrated, the customer viewmay display data centers (DCs) 520 coupled to a single “optical”switching hub, such as vSBOS 510. For example, utilizing vSBOS may allowan operator of a DC 520 freedom from managing one or more of an actualphysical topology and optical network connections that implement vSBOS510. For instance, vSBOS 510 may appear to communicatively couple DCs520 to one another.

Although the reference numerals are utilized via the GUI, the referencenumerals may be utilized with their accompanying descriptions and arealso utilized in displaying reference icons and/or graphics via the GUI,according to one or more embodiments. In one example, DC 520 may referto an icon or graphic in a context of the GUI of the customer view andmay refer to a physical DC 520 in another context. In another example, aphysical coupling 522 may refer to an icon or graphic in a context ofthe GUI of the customer view and may refer to a physical coupling 520 inanother context.

In one or more embodiments, a DC 520 may be coupled to vSBOS 510 viamultiple physical couplings 522. In one example, a physical coupling 522may couple a DC 520 to a border router (not shown), and the borderrouter may couple the DC 520 to one or more physical nodes (e.g., one ormore physical nodes that may implement one or more virtual nodes thatmay implement vSBOS 510). In another example, a physical coupling 522may couple a DC 520 to a physical node (e.g., a physical node that mayimplement a virtual node that may implement vSBOS 510). In one or moreembodiments, a DC utilizing multiple couplings to vSBOS 510 may providefurther resiliency and/or reliability. For instance, DC 520-1 may becoupled to vSBOS 510 via physical couplings 522-11 and 522-12; DC 520-2may be coupled to vSBOS 510 via physical couplings 522-21, 522-22 and522-23; DC 520-3 may be coupled to vSBOS 510 via physical couplings522-31, 522-32 and 522-33; and DC 520-4 may be coupled to vSBOS 510 viaphysical couplings 522-41 and 522-42.

In one or more embodiments, a border router may be or include a type ofrouter that may be located near a border between one or more OpenShortest Path First (OSPF) areas. For example, a border router may beutilized to establish a connection between backbone networks and theOSPF areas. In one or more embodiments, a backbone or backbone networkmay include a portion of a computer network infrastructure thatinterconnects different networks and provides a path for exchange ofdata between these different networks. For example, networks may coupleto a backbone for long distance communication. For instance, a backbonemay include connection points that may be coupled by various mediums fortransporting data, such as traditional copper, optical fiber, and/orwireless (e.g., microwave relays, satellites, etc.). In one or moreembodiments, one or more physical nodes (e.g., one or more physicalnodes that may implement one or more virtual nodes that may implementvSBOS 510) may be coupled to a backbone. For example, a border routermay couple a DC 520 to the one or more physical nodes via the backbone.

In one or more embodiments, a border router may be a member of both amain backbone network and one or more specific areas to which itconnects. As such, for example, a border router may store and/ormaintain separate routing information and/or routing tables regarding abackbone and topologies of the area to which it is connected. In one ormore embodiments, a border router may be or include a point of arrivaland/or departure for that distributed information passes through toconnect to other areas or to a backbone.

As illustrated, vSBOS 510 may include virtual switching elements 525,and DCs 520-1 through 520-4 may be coupled to respective virtualswitching elements 525-1 through 525-4. For example, DCs 520-1 through520-4 may be coupled to respective virtual switching elements 525-1through 525-4 via border routers (not shown). In one or moreembodiments, virtual switching elements 525 may be coupled to oneanother via vSBOS connections 530. For example, virtual switchingelements 525 may be coupled to one another via a full mesh.

As shown, virtual switching elements 525-1 and 525-2 may becommunicatively coupled via vSBOS connection 530-12; virtual switchingelements 525-1 and 525-4 may be communicatively coupled via vSBOSconnection 530-14; virtual switching elements 525-1 and 525-3 may becommunicatively coupled via vSBOS connection 530-13; virtual switchingelements 525-2 and 525-4 may be communicatively coupled via vSBOSconnection 530-24; and virtual switching elements 525-3 and 525-4 may becommunicatively coupled via vSBOS connection 530-34. In one or moreembodiments, virtual switching elements 525 may be coupled to oneanother via multiple vSBOS connections 530. For example, greater and/oradditional bandwidth may be provisioned between two switching elementsof vSBOS 510 via multiple vSBOS connections 530. As illustrated, virtualswitching elements 525-2 and 525-3 may be communicatively coupled viavSBOS connections 530-231 and 530-232.

In one or more embodiments, a vSBOS service may be implemented viavirtual nodes. For example, rather than implementing the vSBOS servicevia physical nodes, the physical nodes may be virtualized. For instance,physical nodes may be virtualized via virtual nodes 550. In one or moreembodiments, a vSBOS service request may be provisioned via creating adedicated virtual optical node. For example, a network provider mayimplement a vSBOS via a virtual optical node. For instance, a networkprovider may implement vSBOS 510 via a virtual optical node 540. Asshown, virtual optical node 540 may include virtual nodes 550, and datacenters 520-1 through 520-4 may be coupled to respective virtual nodes550-1 through 550-4.

In one or more embodiments, virtual nodes 550 may be coupled to oneanother via virtual optical connections 560. As shown, virtual nodes550-1 and 550-2 may be communicatively coupled via virtual opticalconnection 560-12; virtual nodes 550-1 and 550-4 may be communicativelycoupled via virtual optical connection 560-14; virtual nodes 550-1 and550-3 may be communicatively coupled via virtual optical connection560-13; virtual nodes 550-2 and 550-4 may be communicatively coupled viavirtual optical connection 560-24; and virtual nodes 550-3 and 550-4 maybe communicatively coupled via virtual optical connection 560-34. In oneor more embodiments, virtual nodes 550 may be coupled to one another viamultiple virtual optical connections 560. For example, in implementinggreater and/or additional bandwidth of a vSBOS, multiple virtual opticalconnections may be provisioned between two virtual nodes of virtualoptical node 540. As illustrated, virtual nodes 550-2 and 550-3 may becommunicatively coupled via virtual optical connections 560-231 and560-232.

In one or more embodiments, virtual optical node 540 may be implementedvia physical nodes that may include less reliable equipment, and virtualoptical node 540 may be implemented and/or configured such that virtualnodes 540 may endure one or more impairments and/or one or more failuresassociated with utilizing the physical nodes that may include lessreliable equipment. For example, reliability of virtual optical node 540may not be diminished when virtual optical node 540 is mapped tomultiple physical nodes. For instance, each of one or more virtual nodes550 of virtual optical node 540 may be mapped to multiple physicalnodes, and each of one or more virtual optical connections 560 may bemapped to multiple optical network connections.

In one or more embodiments, one or more mappings may be dynamicallyupdated to restore and/or reestablish a virtual node and/or a virtualoptical connection if a network impairment and/or failure occurs. Forexample, a vSBOS service may be utilized via dynamically updating one ormore mappings to restore and/or reestablish a virtual node and/orvirtual connection if a network impairment and/or failure occurs. Forinstance, vSBOS 510 may utilize such a vSBOS service.

Although virtual optical node 540 is illustrated with four virtual nodes550, various numbers of virtual nodes 550 may be utilized inimplementing virtual optical node 540. For example, virtual optical node540 may be implemented with three, five, six, etc., virtual opticalnodes 550. In one or more embodiments, a number of virtual optical nodes550 may correspond to a number of DCs 520 that are coupled to or are tobe coupled to vSBOS 510 and/or virtual optical node 540. For example,the number of virtual optical nodes 550 may correspond to a number ofDCs 520 that are or to be interconnected. For instance, the number ofvirtual optical nodes 550 may be a number of DCs 520 that are or to beinterconnected.

Turning now to FIG. 6, a resilient virtual optical switch mapping 600 isillustrated, according to one or more embodiments. As shown, physicalnodes 640 may be distributed in a geographic region 650. In one or moreembodiments, a physical node 640 may include one or more computingsystems and/or one or more networking devices. For example, a physicalnode 640 may include one or more systems, devices, and/orfunctionalities that may be utilized to implement one or more opticalnetwork systems, as referred to previously with reference to physicalnode 503. For instance, a physical node 640 may include one or moresystems, devices, and/or functionalities that may be utilized toimplement one or more optical network systems, methods, and/or processesdescribed herein.

In one or more embodiments, virtual nodes 550 and virtual opticalconnections 560 may be mapped to physical nodes 640 and optical networkconnections 660 based on one or more of connectivity information,locality information, and resource availability, among others. In oneexample, the connectivity information may include one or more of anumber of spectrum slots (e.g., channels, wavelengths, etc.) between twophysical nodes and a bandwidth, among others. In one instance, a lessnumber of spectrum slots may be favorable, as fewer spectrum slots mayprovide for lesser complexity in information transportation. In anotherinstance, greater bandwidth may be favorable, as greater bandwidth maypermit more information to be transported. In a second example, localityinformation may include one or more physical distances. In anotherexample, determining the network connections for the virtual opticalconnections may include dynamically routing between physical nodesmapped by a first virtual node and a second virtual node and/orassigning at least one wavelength (e.g., spectral slot) between thephysical nodes mapped by the first virtual node and the second virtualnode of the virtual optical connection.

In one or more embodiments, a single virtual node 550 may be mapped toone or more physical nodes 640. In one example, if resiliency is not anissue and/or is not a design preference or attribute (e.g., a customerpreference or attribute), then single virtual node 550 may be mapped toa single one of physical nodes 640. In another example, if resiliency isan issue and/or is a design preference or attribute (e.g., a customerpreference or attribute), then single virtual node 550 may be mapped tomultiple physical nodes 640. For instance, if a first physical node ofthe multiple of physical nodes 640, that is coupled to a data center(e.g., a customer data center such as a data center of data centers 520)and is utilized in implementing single virtual node 550, is subject toimpairment and/or failure, then a second physical node of the multipleof physical nodes 640, that is coupled to the data center, may beutilized in place of the first physical node such that single virtualnode 550 may continue to operate and/or function with little or nodown-time.

In one or more embodiments, a reliability measure and/or a reliabilitydegree of a single virtual node 550 may be based on a number of physicalnodes 640 that the single virtual node 550 is mapped. In one example,virtual node 550-1 may be mapped to physical nodes 640-2, 640-28, and640-55. In a second example, virtual node 550-2 may be mapped tophysical nodes 640-43, 640-44, and 640-71. In a third example, virtualnode 550-3 may be mapped to physical nodes 640-10 and 640-11. In anotherexample, virtual node 550-4 may be mapped to physical nodes 640-39 and640-51. In one or more embodiments, a single virtual node may be mappedto a first physical node and a second physical node and may beimplemented via either the first physical node or the second physicalnode. For example, the single virtual node may be mapped to the firstphysical node that implements the single virtual node. For instance, ata point in time, the first physical nodes is subject to impairmentand/or failure, and the single virtual node may be mapped or remapped tothe second physical node that implements the single virtual node.

In one or more embodiments, virtual optical connections may be mapped toone or more optical network connections that communicatively couplephysical nodes. For example, a reliability measure and/or a reliabilitydegree of a single virtual optical connection may be based on a numberof optical network connections that a single virtual optical connection(e.g., virtual optical connection 560) is mapped. In one instance, avirtual optical connection may be mapped to a single optical connectionbetween two physical nodes. In another instance, a virtual opticalconnection may be mapped to multiple optical connections.

In one or more embodiments, a virtual optical connection may be mappedto multiple optical connections, utilizing one or more physical nodes tolink the multiple optical connections. In one example, virtual opticalconnection 560-12 may be mapped to optical network connection 660-8,physical node 640-19, and optical network connection 660-11. In anotherexample, virtual optical connection 560-12 may be mapped to opticalnetwork connection 660-7, physical node 640-28, optical networkconnection 660-6, physical node 640-2, optical network connection 660-5,physical node 640-19, and optical network connection 660-11. In anotherexample, virtual optical connection 560-12 may be mapped to opticalnetwork connection 660-7, physical node 640-28, optical networkconnection 660-6, physical node 640-2, optical network connection660-10, physical node 640-18, optical network connection 660-9, physicalnode 640-43, optical network connection 660-3, physical node 640-71,optical network connection 660-2, physical node 640-27, and opticalnetwork connection 660-1. For instance, if there is an impairment and/orfailure with a physical node or an optical network connection of avirtual optical connection mapping, another virtual optical networkmapping may be utilized. Although, these examples utilize specificroutes between specific physical nodes utilized by virtual nodes 550-1and 550-2, other mappings may be utilized for other physical nodesutilized by virtual nodes 550-1 and 550-2, and/or other mappings may beutilized for other physical nodes utilized by other virtual nodes,according to one or more embodiments.

Turning now to FIG. 7, a schematic diagram 700 of physical nodes 640that include control systems 200 is illustrated, according to one ormore embodiments. As shown, diagram 700 provides a portion of physicalnodes and optical connections illustrated in FIG. 6. As illustrated inFIG. 7, physical nodes 640-2, 640-19, 640-28, 640-44, and 640-55 mayinclude respective control systems 200-2, 200-19, 200-28, 200-44, and200-55.

In one or more embodiments, a control system 200 may monitor performanceand/or operability of one or more optical network connections and/or oneor more physical nodes. In one example, control system 200-19 maymonitor performance and/or operability of one or more optical networkconnections 660-4, 660-5, 660-8, and 660-11, among others, and/orphysical nodes 640-2, 640-19, 640-28, 640-44, and 640-55, among others.In a second example, control system 200-28 may monitor performanceand/or operability of one or more optical network connections 660-6 and660-7, among others, and/or physical nodes 640-2, 640-19, 640-28,640-44, and 640-55, among others. In another example, control system200-2 may monitor performance and/or operability of one or more opticalnetwork connections 660-5, 660-6 and 660-10, among others, and/orphysical nodes 640-2, 640-19, 640-28, 640-44, and 640-55, among others.

In one or more embodiments, one or more control systems 200 may detectone or more physical node impairments and/or failures and/or may detectone or more optical network connection impairments and/or failures. Forexample, the physical nodes and/or optical network connections may bemonitored for performance and/or operability to detect one or morephysical node impairments and/or failures and/or to detect one or moreoptical network connection impairments and/or failures.

In one or more embodiments, one or more control systems 200 may remapone or more virtual nodes and/or virtual connections in response todetecting one or more physical node impairments and/or failures and/orin response to detecting one or more optical network connectionimpairments and/or failures. In one example, virtual node 550-1 may bemapped to physical nodes 640-2, 640-28, and 640-55 and initially mappedto and/or implemented via physical node 640-2, and one or more ofcontrol systems 200 may remap and/or implement virtual node 550-1 viaphysical node 640-28 or physical node 640-55. For instance, afterremapping virtual node 550-1 to physical node 640-28 or physical node640-55, virtual node 550-1 may be implemented via physical node 640-28or physical node 640-55.

In a second example, virtual node 550-1 may be mapped to physical node640-2, virtual node 550-2 may be mapped to physical node 640-19, andvirtual connection 560-12 may be mapped to optical network connection660-5, and optical network connection 660-5 may be subject to impairmentand/or failure. In one instance, virtual connection 560-12 may be mappedor remapped via optical network connection 660-6, physical node 640-28,optical network connection 660-7, physical node 640-55, and opticalnetwork connection 660-8. In a second instance, virtual node 550-1 maybe mapped or remapped to physical node 640-28, and virtual connection560-12 may be mapped or remapped via optical network connection 660-7,physical node 640-55, and optical network connection 660-8. In anotherinstance, virtual node 550-1 may be mapped or remapped to physical node640-55, and virtual connection 560-12 may be mapped or remapped tooptical network connection 660-8.

Turning now to FIG. 8, a method 800 of operating a vSBOS based on aphysical optical network is provided, according to one or moreembodiments. At step 810, in a physical optical network system, virtualnodes may be determined, based on data centers to be interconnected. Inone or more embodiments, the virtual nodes may be included in a virtualoptical node that provides a vSBOS. At step 815, each of the virtualnodes may be mapped to at least two physical nodes. In one or moreembodiments, multiple physical nodes may be available via a physicaloptical network, and each of the virtual nodes may be mapped to at leasttwo physical nodes of the available physical nodes. For example, avirtual node may be mapped to a first physical node and to a secondphysical node of the available physical nodes. For instance, the firstphysical node may implement the virtual node, and the second physicalnode may implement the physical node when the first physical node is notimplementing the virtual node.

In one or more embodiments, availability of a physical node may bedetermined via one or more physical couplings of a data center to thephysical node. In one example, DC 520-1 may be coupled to physical nodes640-2 and 640-28 via respective physical couplings 522-11 and 522-12permitting physical nodes 640-2 and 640-28 to be available for virtualnode 550-1 to be mapped. In a second example, DC 520-2 may be coupled tophysical nodes 640-43, 640-44, and 640-71 via respective physicalcouplings 522-21, 522-22, and 522-23 permitting physical nodes 640-43,640-44, and 640-71 to be available for virtual node 550-1 to be mapped.

At step 820, virtual links (e.g., virtual optical connections) may bedetermined for pairs of the virtual nodes. In one or more embodiments,at least one virtual link may be determined for each pair of the virtualnodes. In one example, a single virtual link may be determined for afirst pair of the virtual nodes. For instance, virtual opticalconnection 560-12 may be determined for virtual nodes 550-1 and 550-2(in FIG. 5B). In another example, multiple virtual links may bedetermined for a second pair of the virtual nodes. For instance, virtualoptical connections 560-231 and 560-232 may be determined for virtualnodes 550-2 and 550-3 (in FIG. 5B).

At step 825, each of the virtual links may be mapped to at least oneoptical network connection. At step 830, the physical nodes may beprovisioned. In one example, virtual node 550-1 may be mapped tophysical nodes 640-2, 640-28, and 640-55, and physical nodes 640-2,640-28, and 640-55 may be provisioned for virtual node 550-1. In anotherexample, virtual node 550-4 may be mapped to physical nodes 640-39 and640-51, and physical nodes 640-39 and 640-51 may be provisioned forvirtual node 550-4.

In one or more embodiments, provisioning the physical nodes mapped toeach virtual node may include configuring one or more control systems200 of respective one or more physical nodes 640. For example,configuring the one or more control systems 200 of the respective one ormore physical nodes 640 may include configuring the one or more controlsystems 200 of respective the one or more physical nodes 640 to performone or more processes and/or methods described herein. In one instance,the one or more control systems 200 of respective the one or morephysical nodes 640 may be configured to restore and/or reestablish avirtual node and/or a virtual optical connection if a network impairmentand/or failure occurs. In another instance, the one or more controlsystems 200 of respective the one or more physical nodes 640 may beconfigured to map or remap a single virtual node to a second physicalnode (e.g., a backup physical node) if, at a point in time, a firstphysical nodes that implements the single virtual node is subject toimpairment and/or failure.

At step 835, the optical network connections mapped to the virtual linksmay be provisioned. In one example, virtual optical connection (e.g.,virtual link) 560-12 may be mapped to optical network connection 660-8,and optical network connection 660-8 may be provisioned. In anotherexample, virtual optical connection 560-13 may be mapped to opticalnetwork connection 660-11, and optical network connection 660-11 may beprovisioned. In one or more embodiments, provisioning at least oneoptical network connection mapped to each virtual link may includeconfiguring one or more control systems 200 of respective one or morephysical nodes 640. For example, configuring the one or more controlsystems 200 of respective the one or more physical nodes 640 may includeconfiguring the one or more control systems 200 of respective the one ormore physical nodes 640 to perform one or more processes and/or methodsdescribed herein.

At step 840, at least one of a physical node impairment and an opticalnetwork connection impairment that is associated with a first physicalnode implementing a first virtual node may be detected. For example, thefirst virtual node may be virtual node 550-2, mapped to physical nodes640-43, 640-44, and 640-71, implemented via physical node 640-43, andutilizing physical optical network connection 660-3. For instance, animpairment and/or a failure of physical node 640-43 and/or physicaloptical network connection 660-3 may be detected.

At step 845, the first virtual node may be implemented with a secondphysical node. For example, virtual node 550-2 may be implemented viaphysical node 640-71 in response to detecting the impairment and/or thefailure of physical node 640-43 and/or physical optical networkconnection 660-3. For instance, physical node 640-71 may utilizephysical optical network connection 660-2 for a virtual opticalconnection (e.g., virtual link) associated with virtual node 550-2.

The above disclosed subject matter is to be considered illustrative, andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments which fall within thetrue spirit and scope of the present disclosure. Thus, to the maximumextent allowed by law, the scope of the present disclosure is to bedetermined by the broadest permissible interpretation of the followingclaims and their equivalents, and shall not be restricted or limited bythe foregoing detailed description.

What is claimed is:
 1. A method of operating optical networks, themethod comprising: determining a plurality of virtual nodes based on aplurality of data centers to be interconnected; mapping each virtualnode of the plurality of virtual nodes to at least two physical nodes ofa plurality of physical nodes; determining a plurality of virtual linksfor pairs of the plurality of virtual nodes; mapping each virtual linkof the plurality of virtual links to at least one optical networkconnection of a plurality of optical network connections; andprovisioning the plurality of physical nodes.
 2. The method of claim 1,further comprising: detecting at least one of a physical node impairmentand an optical network connection impairment that is associated with afirst physical node of the plurality of physical nodes implementing afirst virtual node of the plurality of virtual nodes; and implementingthe first virtual node with a second physical node of the plurality ofphysical nodes.
 3. The method of claim 1, further comprising:provisioning the plurality of optical network connections.
 4. The methodof claim 1, wherein the determining the plurality of virtual links forpairs of the plurality of virtual nodes includes: dynamically routingbetween the plurality of physical nodes mapped by a first virtual nodeof the plurality of virtual nodes and a second virtual node of theplurality of virtual nodes; and assigning at least one wavelengthbetween the physical nodes mapped by the first virtual node and thesecond virtual node of the virtual link.
 5. The method of claim 2,further comprising: implementing the first virtual node with the firstphysical node based on first connectivity to a first data center of theplurality of data centers, wherein the first connectivity is based on atleast one of a first number of spectrum slots and a first bandwidth. 6.The method of claim 5, further comprising: determining the secondphysical node as a backup physical node for the first virtual node basedon second connectivity to the first data center of the plurality of datacenters, wherein the second connectivity is based on at least one of asecond number of spectrum slots and a second bandwidth.
 7. The method ofclaim 6, wherein at least one of the first number of spectrum slots andthe first bandwidth is different from a respective one of the secondnumber of spectrum slots and the second bandwidth.
 8. A system thatoperates optical networks, the system comprising: a processor configuredto access computer readable memory media, wherein the memory media storeprocessor-executable instructions, the instructions, when executed bythe processor, cause the processor to: determine a plurality of virtualnodes based on a plurality of data centers to be interconnected; mapeach virtual node of the plurality of virtual nodes to at least twophysical nodes of a plurality of physical nodes; determine a pluralityof virtual links for pairs of the plurality of virtual nodes; map eachvirtual link of the plurality of virtual links to at least one opticalnetwork connection of a plurality of optical network connections; andprovision the plurality of physical nodes.
 9. The system of claim 8,wherein the memory media further store processor-executableinstructions, that when executed by the processor, cause the processorto: detect at least one of a physical node impairment and an opticalnetwork connection impairment that is associated with a first physicalnode of the plurality of physical nodes implementing a first virtualnode of the plurality of virtual nodes; and implement the first virtualnode with a second physical node of the plurality of physical nodes. 10.The system of claim 8, wherein the memory media further storeprocessor-executable instructions, that when executed by the processor,cause the processor to: determine the plurality of physical nodes; anddetermine the plurality of optical network connections for the pluralityof virtual links.
 11. The system of claim 8, wherein the instructions todetermine the plurality of virtual links for pairs of the plurality ofvirtual nodes cause the processor to: dynamically route between theplurality of physical nodes mapped by a first virtual node of theplurality of virtual nodes and a second virtual node of the plurality ofvirtual nodes; and assign at least one wavelength between the physicalnodes mapped by the first virtual node and the second virtual node ofthe virtual link.
 12. The system of claim 9, wherein the memory mediafurther store processor-executable instructions, that when executed bythe processor, cause the processor to: implement the first virtual nodewith the first physical node based on first connectivity to a first datacenter of the plurality of data centers, wherein the first connectivityis based on at least one of a first number of spectrum slots and a firstbandwidth.
 13. The system of claim 12, wherein the memory media furtherstore processor-executable instructions, that when executed by theprocessor, cause the processor to: determine the second physical node asa backup physical node for the first virtual node based on secondconnectivity to the first data center of the plurality of data centers,wherein the second connectivity is based on at least one of a secondnumber of spectrum slots and a second bandwidth.
 14. The system of claim13, wherein at least one of the first number of spectrum slots and thefirst bandwidth is different from a respective one of the second numberof spectrum slots and the second bandwidth.
 15. A non-transitorycomputer readable memory device that stores processor-executableinstructions, that when executed by a processor, cause the processor to:determine a plurality of virtual nodes based on a plurality of datacenters to be interconnected; map each virtual node of the plurality ofvirtual nodes to at least two physical nodes of a plurality of physicalnodes; determine a plurality of virtual links for pairs of the pluralityof virtual nodes; map each virtual link of the plurality of virtuallinks to at least one optical network connection of a plurality ofoptical network connections; and provision the plurality of physicalnodes.
 16. The memory device of claim 15, wherein the memory devicefurther stores processor-executable instructions, that when executed bythe processor, cause the processor to: detect at least one of a physicalnode impairment and an optical network connection impairment that isassociated with a first physical node of the plurality of physical nodesimplementing a first virtual node of the plurality of virtual nodes; andimplement the first virtual node with a second physical node of theplurality of physical nodes.
 17. The memory device of claim 15, whereinthe memory device further stores processor-executable instructions, thatwhen executed by the processor, cause the processor to: provision theplurality of optical network connections.
 18. The memory device of claim16, wherein the memory device further stores processor-executableinstructions, that when executed by the processor, cause the processorto: implement the first virtual node with the first physical node basedon first connectivity to a first data center of the plurality of datacenters, wherein the first connectivity is based on at least one of afirst number of spectrum slots and a first bandwidth.
 19. The memorydevice of claim 18, wherein the memory device further storesprocessor-executable instructions, that when executed by the processor,cause the processor to: determine the second physical node as a backupphysical node for the first virtual node based on second connectivity tothe first data center of the plurality of data centers, wherein thesecond connectivity is based on at least one of a second number ofspectrum slots and a second bandwidth.
 20. The memory device of claim19, wherein at least one of the first number of spectrum slots and thefirst bandwidth is different from a respective one of the second numberof available add/drop ports of the second number of spectrum slots andthe second bandwidth.